Electron Configuration Orders?

[KC Navarro_1H]

When doing electron configuration, do you have to keep the same n-values together?

For example, I wrote the electron configuration for antimony (Sb) as:

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^3

Or [Kr] 5s^2 4d^10 5p^3

Would it be different if I grouped it by n-values? Like:

1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p^6 4d^10 5s^2 5p^3

Or [Kr] 4d^10 5s^2 5p^3

If they aren't different, which one is preferred? Thank you!

[Bryan Jiang 1F]

Even though the same information about the electron configuration is displayed by both of those ways, one should still order the electron groupings by n-values first to denote the fact that the shells are the primary differences in energy levels. Dr. Lavelle mentions this preference for n-value order near the end of Week 4 Friday lecture with the example that ground state scandium, Sc should be written as [Ar] 3d¹ 4s², NOT as [Ar] 4s² 3d¹.

[joannehaddad]

To double check your answer, make sure that your configuration is written in the order of the n - value, so all the sub-shells associated with 3 are put before any of the sub-shells associated with 4, for example.